Zilog's Z80 8-Bit Microprocessor

Description

The Z80 microprocessor is an 8-bit CPU* with a 16-bit address bus
capable of direct access of 64k of memory space. It has a language
of 252 root instructions and with the reserved 4 bytes as prefixes,
acceses an additional 308 instructions. The Z80 was modeled after the
8080 and contains the 78 - 8080 opcodes as a subset to it's language.

Programming features include an accumulator and six eight bit registers
that can be paired as 3-16 bit registers. In addition to the general
registers, a stack-pointer, program-counter, and two index (memory pointers)
registers are provided. While not in the same leauge as the 80486 or
68000 series, the Z80 is extremely useful for low cost control
applications. One of the more useful features of the Z80 is the built-in
refresh circuitry for ease of design with DRAMs.

The Z80 comes in a 40 pin DIP package. It has been manufactured
in A, B, and C models, differing only in maximum clock speed. It also
has been manufactured as a stand-alone microcontroler with various
configurations of on-chip RAM* and EPROM*.